Water-tube boiler



A. COTTON. WATERTUBE BOILER. APPLICATION FILED MAR. I6, 1920.

@Mmmm m w22 titi ALFRED CTTON, 0F SF2. LOUISX MSSOURI, ASSGNOR T0 HEENE BOILER CMANY, 0

ST. LOUIS, EIHSSGUR, A CORPORATION OF MXSSOUR.

wafrnnfanna nonnen.

application and name 1e, i920. semi no. ascesa To all 'lc/wm it may conve/n g A Be it known that l. ALFRED Co'rToN, a citizen ot' the llnited States, residing at St. vLouis liiissouri, have invented a certain new and useful improvement in YVater-'lube Boilers, ot' which the following is a full. clear`r and exact description. such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to water tube -boilers of the type that comprise a plurality ot banks ot' upright water tubes connected at their upper ends to transverse steamand-water drums.

Tbeobjects ol tbe invention are to increase the vefliciclncyl ot boilers ot' the type mentioned: obtain more complete combustion and eliminate smoke: produce drier steam; increase the steaming capacity without vincreasinzcr tbe size of the boiler and simplify the constrution ot boilers of the type 'referred to.

The ligure ot' the drawing is a vertical ectional view ot' a boiler'eml'iodying my invention; v

The circulation in the regular Stirling boiler is upwards through the iront tube bank into the iront steam-andwater drum, through the water circuiators to the middle steainland-water drum. and downward through the middle tube bank to the muddruxn. lt is well known that the amount of water evaporated per unit ot heating surface is enormously greater in those parts of the heating surface exposed to radiant beat from the tire, than in those parts which are heated by impingement ot' hot 'gases only. lt is also well known that, as 'a consequence of this, the greatest amount oi water evaporated per unit ot' heating surface takes.

place in the front tubes ot' the t'ront bank in. the regular bt-irling boilers.

As the whole of the upward flow ot the water in the usual Stirling boiler is into the lront steam-andswater drum, and as the water circulators connecting the front steamand-Water drum with the middle steam-andwateipdruni are necessarily restricted in number and consequently in their total cross-sectional arctay the water-tends to accunulate in the front steam-aud-water drum. ln other words, the water level in the trout straniand-water drum rises when tbe boiler is driven at even moderately high rates, lowing tothe restricted flow area between the front and middle steam-and-Water drums. Also owing to this restriction, the pumping action of the circulatory vflow (on more correctly, the pumping action which causes the circulatory tiow) up the 'front tube bank tends to slightly lower the pressure in the mud drum, so that the water level in the rear steam-and-water drum tails below the normal or average level. At high drivingr rates this et'ect is so marked that the water level in the rear steam-and-water drum sometimes falls until it is a Jfew inches below the bottom of 'the drum, thus causing the upper ends ot the tubes in the rear bank to become dry and overheated to such ar de grec that their expanded joints into the drum shell give trouble by leakage.

A 'further and a serious trouble with the ordinary Stirling. boiler, caused by the rising of the water level in the front steamand-vvater drum, is that in conjunction with the turbulent state of the water therein, caused by the whole up 'ard flow of steam and water being concentrated into said `iront steam-and-water druni7 a great deal ot water is carried over with the steam into the midthis water remains in suspension in the steam leaving the boiler by the outlet on thcmiddle steam-and-"Water drum. Recognizing this objectionable feature, inventors have sought to dry the steam by such means as placing the steam outlet on the rear steamaml\vater drum. using this drum as a separating chamber; by carrying the steam to the rear drum and back into a. pocket or compartment in the middle drum, or by adding another drum above the three steamand-water drums.

Another objection to the regular Stirling boiler is that the furnace gases rise immediately into the `front tube bank, thus causing said gases to be chilled below their igni/ tion. point before combustion is complete and, resulting in loss ot' eliiciency and lxeavI,7 smoke. This objectionable characteristic bas also been recognized by inventorswho have sought to improve the facilities for combustion by placing a baille at or near the front of the front bank ot' tubes, so as tocanse the gases to. risc the i'nil height ot the combustion chamber before entering the 'fronthank of tubes. Vlhis remedy is objectionable. in that this front baille is not as easy ol' access or construction, or as cheap to in asi fie

'type stell, es are baffi/e simply leid ou llie lou l of the bunks.

My invention improves -lioilers of the Stirling type by 'mectiug end removing;- :ill o- 'he dieedvunuges and objectionable clieracerislice above referred to in e. `very simple manner, zuid it 'provides uu ellicieul; and accessible boiler lgieceu be coustrueleil es cheaply es "alie regular Sirling boiler even more cheaply. Bromlly eetecl, invention coisisgs in, arranging the ueee ol e Water 'lube boiler of `alie general pe previously referred 'to iu. four diemict neuke, eecli of which has u'difereut functions and which may be cullerl lle radiant heal; barili' A, the coriveciefl licei beul; B, the (lowucomer bunk C, und he eceucmizer lie/ink D. The freut benk or radiant heel; baul: A consists of only e few rows of tubes that ere exposed to the radiant heet of 'lle und of the combustion chamber El. ln the preferred coueirucicn the reflieul; lieu; beul( formed lLiy-'wo rows of iulocs which are ilui only cultes liscizergiiiigg ijilie lie "front seem-eufl-Weter drum 1l.. liti. Home iuseuces three rows cf tubes; may lie used in lle reclieiit licei; beuk, bui. iu ll ille crcseeecicuufl aree of 'bile lubee o rzuiiemi heut beuk will be less *than the cross-sectional urea of tubes mi alle veclzecl heels beuk liucc the flow of scum uml water ino the from', @tenue-ufl Water rum is very much lees "in my improved .boiler than in die usuel Sirliug boiler, *che Weeii' iu the from drum of my boiler is much calmer. Consequently, l. um enabled to make the from; drum l smaller than is the usuel pre-slice und. still get much better separation of the steam und Waller, As. l. lfm-ve even more roem for Weier ciivculeors 2 "beween lille drumf and the middle sleeiu--and-Water drum 3 will; lese weine '5.o lGW through Seid circuleiiors 2 allen iirzlie regular Stirling boiler', there is less rise of the Water level in the front drum, with further irsxprovemeu'k iu falle separation of the steam. and Water. This irriproved. separation ol the steam zuid We ler or reduced tendency to' curr] Weier over uili the Steam liroii the iront drum l into the seam space of the ixiiddle drum allows my boiler tosupply drier seem when driven at ratos much higher fixen is considered reasonable practice Willi lie regular Stirling boiler. v

The second lube baul; ll of my boiler muy be described es exposed to couvecteil heel; only. Thie secouzl ouali discharges oli rectly into the mulrllc Steenremi-wauw (l1-um 3, eml though not necesaryv li prefer to make this middle drum larger lum is Elie usuel pracice iin. boilers of ilie lirling l :iiueuuliled to lo this wiliou; incre-use of the total cost ol',ccnsmiiciou of lille lfioiler, because l make lie 'from esteem emlweer @ruin l smaller @lieu usual, es already expleiumi. enel llie reer steemmucl- Weiser drum Ll Smaller than is lieusuul prec tice. es hereinafter explained. Since the Weiter flowing the second beul: er con veccil heut beuk l Hows clireoiy across the middle eteeiu--end-wevter drum 3 Wihout lim/ing lo encounter the resieence iso ef any wucer circuletors. ee in il '1 icguler Stirling boileryilic ow to. lle if beul; or (lower-,omer ofi-uli (l my bei 1re free. @wing to lle increased Size of lie micidle eleumemlwvuer drum 3, :md to less water being carried oy lie Steam peseiug from elle 'from eLezim-uu-Waer drum into the .middle drum leroug'li alle seam circuluiere 2n. @he fieem leaving 'lle Seem space of linie middle drum is much drier tiren 'in the ueuel Stirling boiler. S0 much is this the case the steam outlet of my boiler may be. placed on the mirldle il um of the boiler. il prefer, however, to carry 'che sleem frein the middle drum 'olli rear rruu7 inlirough circuleers 5, o sill furher lie eutreiiied welerfrom the seem und piece lili-e eleem oule 6 ou lie reef imm fi ef elle boiler. l

The izliirfl beuk of bulbes C of my boiler is lle downeomeir umili. li have explained how che Waiter enters ibis bank from the middle drum E2 wili very much less resisttlieu im the ordinary SLirling boiler.

The lourg er ecouou'uzer barili D is con riececl between the rear seem-eud-weer drum 4: ande lower chamber 7 which may either cousisa of e mud drum or e number of mud drums connected tegether iii 'the usuel manner. llllheu e plurality of mud drums are used, it is esseutieb heWcver',-tliav the lower ends oi' ille luloes oi second and.

third bein-lis B und C, respecively, be con neclpecl to the sume muil drum, so us to per mit lle water ibut returue *ahrcugli the clowriconicr beukio flow directly across the mud drum to the lower enfle of loe ubes of the upcomer bank B Wiliout hei/luglio encounter the resist-moe to liow of :my wav ter circuletors. As it is not good practice lo allow very cold feed water 'go flow down lle economizer bunk l). then some condensation ci' water vapor iu the gases muy lelie piece on the tubes, resulting in external corm mision, l prefer lo connect u few water circulecrs 8 between the midille and roer steum-end-Wuter drums 3 und 4L. respectively. The liet Weiler flowing l'irouggli l'iege circululiore mime with uml raises lli-e temperature ui lil/ie 'leed waiter suliicieully sie avoid the 'rouleie joer mentioned. The flou* lirougli tlieie circulaors 5l also lends to prevent :my

olijeciouelile lowering of lle wer level in the regir @mineral-Water lrum il; su; :already mentioned; bulv it muet lie remeiulierefl lrie.

ovine' u the avoidance el' nearly/ell elle resricieu lo *circulueou present in the usuel eee lov

rasante Stirling boiler, by reason 'of all the circulating water having to pass through the water circulators, except that short-circuited by flow' reversals within the tube blanks, the lowering ot' the water level in the rear steanbandbvater drum 4 of my boiler is small and unobj'ectionable, even, at very heavy rates oit driving. As ,the steam which enters the rear steam-and-water drum l of my boiler is much drier; than that leaving the middle drum ot' the usual Stirling boiler, much less steam space in the rear drum is necessary for further drying', and as there is much less lluctuation ol" the water level in i this rear drum, as just explained, lam enabled to `make it smaller than usual with consequent reduction in the cost ot construction. rlfhe ballles of the boiler can be arranged in various ways without departing from the spirit of my invention, and while l have herein illustrated only one form ot balil'ling means, l wish it to be understood that it is immaterial how the battles of the. boiler are constructed or arrange-d, so long! as the boiler isequipped with four banks of water tubes combined with a mud drum and three steam-and-water drums, or `equivalent de vices, in such a manner that the water in the first bank oltubes will circulate upwardly through same into the lront steamand-water drum, and the water in the second bank or tubes will circulate upwardly through same into the middle steam-andwater drum and then through said middle drum to a third bank or downcomer bank of tubes which lead to the mud drum.v ln the form of my invention herein illustrateda front baille 9 extends upwardly 'from the mud drum 7 at the rear side of the radiant heat bank A,\the upper end et said being spaced away from the iront drum l", as shown in the drawing.` 'A second baille l0 extends downwardly' from the middle drum 3, between the second and third banks E and C, respectively, to a point in proximity to the mud drum 7, and a third baille ll ex tends upwardly from the mud drum at a point between the third and Jfourth banks, the upper end of said third baille lltermlnating at such a point that a space 1s providedY for the passage ot the ,frases intothe last tube bank D down which the gases travel to an outlet l2. v

A most important advantage resulting' from my novel arrangement of tube banks, is the way in which a spacious hot combustion chamber X is naturally provided without any awkward devices or complicated ballling means in said chamber, it being possible with my boiler to support the front baille 9 by the rear tubes of the radiant heat bank A. The simplicity of the battling, the ease with which it is erected.l and its accessibility are indicated clearly in the drawinw` which also shows how the spaces between the sist et a small number of rows of tubes,

which is an essential feature of my inven- Y,

tion, the L(gases are not unduly chilleddur ing 'the tirst pass, while the temperature of the combustion chamber is sutllciently reduced by the presence of the tubes of the front bank to avoidi undue wear and tear of brickworlr and furnace parts.

lt will be seen thatl my invention does not consist in merely a splitting up of existing tube banks. ylhus, my firstand second banks are not attained by simply dividing the front tube banlr oli the usual Stirling boiler, for this would not accomplish the highly important result of reducing the flow vof steam and water to the front drum, and consequently, relieving the congestion in the water circulators between the liront and middle steam-and-water drums. lt would not reduce'the litt of the water level in the front drum and would not reduce the tumult in the front. drum ;v and by 'failing to accomplish these. results, it would not reduce the amount of water carried over bythe steam flowing from the .front drum into the middle steam-and-water drum. l't would not enable the front steam-and-water drum to be made smaller, and it would not avoid the objectionable lowering` of the water level in the rear steam-and-watei" drum, due to the restriction caused by the steam circulators between the liront and middle and-water drums being congested. lt will also be seen that my invention does not consist in merely a splitting up ot the middle tube bank of the usual Stirling boiler into two banks, o'r this would also fail to accomplish any of the results mentioned in the last paragraph. 'The only etlect or' this would be to make two tgras passes instead oi one, with each pass over a small bank of tubes, and would not in any way remove the objections which lie against the Stirling liront bank, or, indeed, make any change in it whatever.

Havingr thus described my invent-ion, what l claim as new and desire` to secure by Letters Patent is:

.1. water tube boiler, comprising atleast two elevated transverse steam-and-.water drums, water circulators connecting; said drums together, a transverse mud drum, a radiant heat bank of upflow tubes leading* upwardly 'from said muddrum to one of said elevated drums and constituting the sole source of water supply to said elevated drum. a separate and distinct convected heat bank of u pllow tubes spaced away from said radiant heat bank and connected to the other Elli gua

elevated drum for causing the 'remainder ef thefwetei rising from seid mud dimm to cireulete npwerdly te said other elevated cli-um, e bee eirenged between seid radiant beet benk and said cenveetul heet bank, a eoopereting baille for causing the lire gases to flow downwedl-y among the tubes of the eonveeted beet benk, end downeomer tubes leerling 'i'om one ef seid elevated diums directify* to seid mnd` drum 2 A water tube beilei, Comprising three' between tbe iedisnt heet benk and tbe conveeteel heat benk, downeomei tubes leading from tile middle dimm to the mud drum, and en eeonomizei' benk of tubes leading from tbe reel' steemend-weter drum to the mud drum.

witter tube boilei, ceinprising thi'ee elevated tiensverse steem-mid-waterl drums,

sem-aind-wetei eii'euletois connecting,- tbe fiont drum with tbe middle dirum and the middle drum with the reen dimm, :i trans Verse mud drum, e iedient beet bank of up flow tubes leading upwardly from the mnd neewie dzm to the front steemend-watei' drum and constituting the sole source of water supply te said front drum, e seperate end distinct conveeted beat bank of upflow tubes spaced away from the radiant heet benk for conducting the remainder of the water supplied to the mud drum upwardly to the middle steztni-end-weter drum, e baille arifanged between the radiant heatbenk and the `convected beat bank, s cti-operating baille for causing: the fire gases to Jflow downwardly smong the tubes of the convected heat bank,

downeomer tubes leading from the middle steani-end-water drum to the mud drum, end en-eeonornizer bank'of tubes leading from the resi' steam-end-Watei' drum to the mud drum.

Il. A. water tube boiler, cemprising atleast two elevated transverse steexn-endwe er drums, ai transverse mud drum, e redie't heet z'st benk of upflow tubes leading from the mud drum to the front steam-and-water drum and srienged et the resi' of the comn bustion chamber outside of the main path of flow of the gases, water circulatoire edn meeting said elevated steamendweter drums l together, a convected heetl second bank of' upiiow tubes leading from the mud drum to the second steam-endwater drum for causing tbe remainder of the weten rising from the mud drum to pass directly into'sad seeond steemandwater drum, e beiile between the first and second banks, end downcomer tubes leading from the second steam-endweter drum directly into said mud drum.

'flessen comme 

